Exchange 2013 CU2 Public Folder Issue Discovered

Microsoft is warning of a newly found issue in its recently released Cumulative Update 2 (CU2) for Exchange Server 2013.

CU2 was released earlier this month as part of Microsoft's new quarterly update release schedule for Exchange 2013. This faster release cycle is designed to support organizations that use hybrid messaging scenarios. For instance, applying Cumulative Updates on a regular basis helps organizations that use Exchange Online services along with premises-based Exchange Server 2013, so that those two implementations run the same code, Microsoft has argued. However, in practice, Microsoft's frequent updates for Exchange have tended to come with unfixed problems in recent years. This CU2 release was no exception.

The problem this time is associated with moving public folders, according to a blog post by Ross Smith IV, principal program manager for Exchange customer service at Microsoft. When either a primary or secondary public folder gets moved after installing CU2 for Exchange 2013, then there's a possibility that "the permission structure" for users on those public folders will get lost.

The primary public folder is located in the root. It's called the "RootPublicFolderMailbox." Secondary public folders are "childs" of the root folder. Moving either the primary or secondary public folders causes the permission structure to switch to using the default access control list for user access.

Those organizations that installed CU2 for Exchange 2013 and subsequently moved their primary public folders will have to "manually reassign permissions," according to Smith. If the secondary folders were moved, then there's a PowerShell cmdlet that can be used to replace the permissions.

Microsoft plans to issue an Interim Update to fix this public folder problem "in the near future," Smith indicated. He also promised that Cumulative Update 3, when released, would include such a fix. In the meantime, Microsoft is recommending that those organizations that installed CU2 for Exchange 2013 should not move their public folders. They should just wait for the update to arrive, although it's not clear when that will be.

Smith said that the Exchange team had thought that it had tested this CU2 release for this scenario. The Exchange team typically runs more than 100,000 automated tests before product shipment, he added. Microsoft is reviewing its internal processes to avoid such issues in the future, he said.

Many of Microsoft's update problems have been seen with older Exchange products. For instance, Microsoft had a copy-and-move problem associated with public folders used with the Outlook e-mail program, which was associated with its Update Rollup 4 release for Exchange Server 2010 SP1. That problem didn't get fixed in the next release, RU5, causing much IT pro grumbling.